Early one morning at Primanti Brothers, in the middle of Pittsburgh's Strip District, Antonia Corradetti is constructing a sandwich so big it would make Dagwood blanch. A fixture behind the long diner counter, she flips a wad of just grilled corned beef onto a thick slice of Italian bread. Then, yanking a basket of oil-dripping french fries directly from the deep fryer, she plunges her bare hand into the heap, extracts a fistful of steaming potatoes, and smashes them on top of the beef, so you can hear the sizzle when the smoking spuds greet the meat. Surprised there is no echoing sizzle coming from Corradetti's hand, I'm ready to dial 911, but she seems indifferent to her five-finger fire walk.

"I've only been doing this for 28 years," she says with a shrug, in a strong Italian accent.

"I can do a thousand of these an hour." But the pain? "Well the first time I did it, it was kinda hot, but the grill is a good conditioner." Corradetti laughs, holding out beautifully manicured hands as soft as a baby's cheek.

Locals call Corradetti's literal handiwork the official Strip sandwich—not just because others have copied it but because it mirrors the district's own history. Dating back to 1933, when the Strip was still the exclusive turf of wholesalers delivering produce out of mammoth brick warehouses, the sandwich was aimed at a fail-proof market. For the truckers, who were Strip royalty, nothing tasted better than the meat-and-potatoes meal they could hold in one big hand, while they steered with the other.

Now the sandwich is consumed mostly by late-night clubbers, but it still signifies the way the Strip guards its traditions, starting with its own defining look. Forget designer makeovers. You can see Pittsburgh's high-rises in the near distance, just to the south, but the restless development largely stops at the Strip's border, where the hulking brick buildings still throw long shadows like something out of a Hopper painting.

The district's survival, though, was never a sure thing. It underwent a slow decline that began in the Depression, when the warehouses first started to lose business. But by the 1970s the wholesalers were opening retail shops, and by the '90s a fresh generation of style setters had moved in, launching the boutiques, galleries, and dance clubs now lining Penn Avenue, the Strip's version of Main Street. The inevitable conversion of warehouses into lofts followed, and the Strip morphed from homey to high style.

Pittsburghers call Primanti Brothers's fries-and-coleslaw-embellished sandwiches the official sandwich of the Strip District. What food is special to your zip code?

In More to Explore the National Geographic magazine team shares some of its best sources and other information. Special thanks to the Research Division.

Between 1860 and 1915 the Strip District's population increased from about 12,000 to 18,000. German, Irish, and native-born American artisans who had dominated the area in the early 19th century were being outnumbered by unskilled workers from southern and eastern Europe who were flocking to the steel mills. Crowded conditions, crime, and disease were rampant. With no indoor plumbing, several families shared a single water pump, and outbreaks of typhoid, scarlet fever, and diphtheria were common.

The city's first public bath was built in 1897 at 16th and Penn in hopes of stemming the spread of disease. In 1907 the Civic Club of Allegheny County constructed a two-story People's Bath, which served more than 230 patrons a day at its peak and operated until the late 1920s.

After World War I the steel mills in the district shut down or relocated to areas with more space. As steel production declined, workers moved away. Even with a flourishing wholesale produce business in the 1920s and '30s, the Strip's population never recovered. It has continued to decline every decade since the 1920s.

—Cate Lineberry

Neighbors in the Stripwww.neighborsinthestrip.comFind out what's happening in the Strip and take a walking tour of some of the area's most interesting historical spots.